DE-U 8219 588 discloses a light curing device which has a proximity switch. The proximity switch comprises an infrared light source and an infrared detector. When a tooth replacement part is brought into the exposure range of the polymerization light source, which is formed as a halogen lamp, the infrared detector switches the halogen lamp on by means of a switch that is not represented, so that the exposure to light begins.
Although this solution has the advantage that no special action is required for the light curing device to be switched on, the light curing device is necessarily switched on when anything comes into the range of the light source, for example even when a user reaches into the exposure range, for example for cleaning purposes. However, frequent switching on and off is detrimental to the service life of halogen light sources. Moreover, the solution presented there is dangerous to a certain extent. If the protective shield provided there is removed for cleaning purposes, it may be that, as a result of the automatic switching-on function, the user is inadvertently dazzled by the highly concentrated beam of the halogen lamp if the halogen lamp is inadvertently switched on.
It has been known for some time to provide light curing devices with program control. As a result, the required exposure time does not have to be estimated, but can be preset in a program-controlled manner. It is also possible to create specific emission programs, for example color changes or intermittent emissions. Such solutions have been known for some time, an example of such a solution that may be cited being the modern Bluephase™ system of the present applicant. The special high-energy light-emitting diodes with a luminance of 1100 mW per cm or even 1600 mW per cm allow the required curing times to be significantly reduced, for example to ten or even five seconds, depending on the polymer that is used.
Such program controlled devices in most cases require an initialization when the voltage supply is switched on, the microprocessor which performs the program control being activated and the menu choice for the desired programs also being provided.
For the initialization, the actuating switch for the light curing device is briefly actuated once when the light curing device is removed from the base station or the rest. The initialization is started by pressing the actuating switch once, and after three to five seconds the light curing-device is ready for light curing.
If the dentist inadvertently does not hit the actuating switch correctly or inadvertently does not press it, initialization does not take place. In this case, the actuating switch would be actuated for the first time at the intended start of the light curing cycle. If the dentist notices this, the curing cycle is delayed unnecessarily, if on the other hand he does not notice it, the desired curing could fail to take place—at least to the extent intended.
In order to ensure signaling that the light curing device is ready, it has been proposed to emit an audible signal when the initialization process is completed. However, such an additional acoustic signal disturbs the desired peace and quiet in the environment of the dental practice and also demands the attention of the dentist, making such a solution fundamentally unsatisfactory.